William Osler Health System Foundation and the broader William Osler Health System community mourn the loss of a cherished colleague, mentor, and friend, Ken Mayhew, President and CEO of Osler Foundation.

A respected leader in Canadian philanthropy, Ken dedicated his career to bringing people together in support of causes that strengthen communities and improve lives. Known for his thoughtful leadership, generosity of spirit and genuine warmth, he inspired those around him to believe in the power of giving and the difference it can make for patients and families.

Ken joined Osler Foundation in 2012, where he spent more than a decade championing the role of philanthropy in advancing health care across the region. Under his leadership, Osler Foundation deepened its connection with the community and expanded its impact, helping ensure that Osler’s hospitals continue to deliver exceptional care close to home.

Prior to joining Osler Foundation, Ken spent more than 20 years with the MS Society of Canada, where he played an important role in advancing research, programs, and services for people living with multiple sclerosis. His commitment to the philanthropic sector extended well beyond his professional roles. Ken was an active volunteer and leader, serving as Chair of the Association of Fundraising Professionals Canada and President of the local AFP chapter, where he mentored colleagues and helped strengthen the fundraising profession across the country.

Ken’s contributions were recognized with numerous honours throughout his career, including the prestigious King Charles III Coronation Medal, Fundraiser of the Year from the Greater Toronto and Golden Horseshoe chapters of the Association of Fundraising Professionals, and recognition as a Paul Harris Fellow from Rotary International. His work was also featured in Peter Mansbridge’s book How Canada Works: The People Who Make Our Nation Thrive, which highlights Canadians whose leadership helps shape the country.

Those who worked alongside Ken remember him not only as an accomplished leader, but as someone who always valued people above all else. He had a remarkable ability to connect with others—whether donors, volunteers, physicians, staff or community partners—and to make each person feel that they were part of something meaningful. His wisdom, humility, and sense of humour made him a trusted colleague and a steady presence for the Osler Foundation team and the broader Osler community.

Ken’s passing is deeply felt by his colleagues, as well as by the many donors, volunteers, and partners whose lives he touched. Our thoughts are with his family and loved ones, whose support throughout his life allowed him to devote so much of himself to the causes he believed in. Ken leaves behind a powerful legacy—one built on compassion, collaboration, and a steadfast belief that when communities come together, extraordinary things are possible. Though he will be profoundly missed, his impact will continue to be felt in the care provided to patients and families across our region for years to come.

Ken’s family and loved ones are profoundly grateful for the dedication and compassion of the incredible health care team across Osler who cared for him. Those wishing to make a gift in Ken’s memory can do so here, or at the link below.